in nitromethane 48 h; Ambient temperaturefurther solvents;

1: 69 percent / nitromethane / 48 h / Ambient temperature; further solvents 2: 80 percent / (n-Bu)4NBr, aq. NaOH / 0.5 h / Heating 3: LAH*bis-THF / tetrahydrofuran / Ambient temperature; further reagents and solvents 4: 83 percent / BF3*Et2O / CH2Cl2 / 1 h / 0 °C 5: 85 percent / KOH / 2-methyl-propan-2-ol / 1 h / Heating View Scheme